As an analysis method of an internal structure or a defect of a semiconductor device or the like, a cross-section processing and observation method of performing cross-section processing of a sample with a focused ion beam, exposing a cross-section including a desirable structure or a defect, and observing the cross-section with a scanning electron microscope, has been known. According to this method, since a desirable observation target in the sample can be exposed pinpointedly, it is possible to rapidly observe the structure or the defect.
In addition, a method of repeatedly performing cross-section processing and cross-section observation, and constructing a three-dimensional image of an area which is subjected to cross-section processing by combining the plurality of obtained cross-section observation images has been known (see JP-A-2008-270073). According to this method, it is possible to construct the three-dimensional image of the observation target.